HELP!! Weird cold start problem 1990 100Q

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Aug 6, 2006 | 10:28 PM

paulfern2000

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HELP!! Weird cold start problem 1990 100Q

Hello to all.

I have a problem on my 100Q.
First I should mention this is a Euro spec 100Q with 2.3 (NF) motor and it has no AC or even check control. It is preety much bare bones..but very very realiable ...that is until a few days ago.
Plugs and wires were changed last month, it has a new fuel pump as well, oh yes and a new Oxygen sensor.

A few days ago I started getting a weird start problem when I start the car cold.
It starts up right away ..but after a meer 8-10 seconds shuts down & stalls.

After about 5-6 restarts it does start to improve but even on the last one I have to give it a little gas to prevent from stalling..it almost sounds like super fuel dragster at some point. After it warms up however all starts running well.

I have to admit I have been around these cars since 1994 and I have never seen one do this ..anyone with an idea?

Aug 7, 2006 | 12:47 AM

mcorrow

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sounds like a failed temperature sensor to me..

Aug 7, 2006 | 02:03 AM

paulfern2000

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Darn I forgot to mention the temperature sensor is new also.

I am talking about the one on the water neck..coming the engine.

Aug 7, 2006 | 02:40 AM

mcorrow

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What happens if you start it cold and then give it some gas?

Extra fuel should only be necessary when cold and idling.. as soon as you give it some gas, it should no longer need extra fuel.. Sounds like cold start valve shutting off too early (which is why I suggested temp sensor).. Is the WOT(idle switch) working?

Aug 7, 2006 | 03:29 AM

boxerfan

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Sounds like a fuel problem alright...

Since it is starting OK it seems as though the CSV is working alright. 8 to 10 seconds seems in line with the warm up cycle of the WUR. Check the control pressure if you have the gear. If the CSV is firing and allowing a start and then the WUR allows the control pressure to remain high then the mix will lean out. Watching the voltage on your O2 sensor will help understand what's going on. I'll bet the opposite is true. I'm thinking the mix is OK because of the CSV and then when it shuts off then the mix is too lean.

A couple of simple things to check? Check your boot and plumbing from the CIS dizzy to the intake manifold. Check your motor to ECU grounds.

Feels like I'm missing something... I'll keep chewing on it. Hey... how's the DTM spoiler coming? And the matching air dam for the V8?

Aug 7, 2006 | 06:21 AM

paulfern2000

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Hey this is good info thank..just one Q...what is WUR?

Spoiler is doing well should be out within few weeks....it will be anounced.

Aug 7, 2006 | 06:33 AM

paulfern2000

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Give gas!!

On first start if I give gas the motor will stall no matter what I do..
Second start if I give gas it will sputter a bit then stall.
Third start ..give gas..will try to idle..and die
Fourth..getting better...
Fifth...Give gas and RPMS...will go up and try to die ..almost dead give some more gas...will come to life..
Sixth start..give gas...IT'S ALIVE!! after that no problem.

I am also suspecting the cold start valve (#6 injector)..
I wonder if they be cleaned and just reinstalled?

I have to check the idle switch...have not thought of that one..but I doubt it as well since it behaves under any other condition OK..will check..thanks.